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US 9,001,095 B2Granted
Illumination sensing device having a reference voltage setting apparatus and a display device including the illumination sensing device
AssigneeSamsung Display Co., Ltd.
InventorsSung-Un Park, Soon-Sung Ahn, Do-Youb Kim
Life of this patent
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Abstract
A reference voltage setting apparatus including: a current generator having a first device to supply a first dark current and a second device to supply a second dark current; a first operational amplifying unit connected to the current generator; and a voltage setting unit connected to the first operational amplifying unit and setting a reference voltage having a compensated offset voltage of the first operational amplifying unit, and an illumination sensing device and a display device including the reference voltage setting apparatus.
Claims13
An illumination sensing device comprising:
- an illumination sensing unit comprising:
- a first dark diode configured to generate a first dark current;
- a first photodiode electrically connected to the first dark diode in series and configured to generate a photocurrent and a second dark current;
- a first operational amplifying unit connected to the first dark diode and the first photodiode;
- and
- an illumination calculator connected to an output terminal of the first operational amplifying unit;
- and
- a reference voltage setting unit configured to determine a reference voltage for the illumination sensing unit and to provide the reference voltage to a non-inverting input terminal of the first operational amplifying unit, the reference voltage setting unit comprising:
- a second dark diode configured to generate the first dark current;
- a second photodiode electrically connected to the second dark diode in series and comprising a light shielding film for generating the second dark current;
- a second operational amplifying unit connected to the second dark diode and the second photodiode;
- and
- a voltage setting unit connected to an output terminal of the second operational amplifying unit and configured to determine the reference voltage,
- wherein the reference voltage is determined to compensate for an offset voltage of the first operational amplifying unit and a difference between the first dark current and the second dark current.
11 more elements
A display device comprising:
- a pixel unit comprising a plurality of pixels;
- an illumination sensing device sensing illumination of external incident light;
- a plurality of drive units operating the pixel unit;
- and
- a controller to control the drive units and brightness of data displayed in the pixel unit according to the illumination of light sensed by the illumination sensing device,
- wherein the illumination sensing device comprises:
- an illumination sensing unit comprising:
- a first dark diode configured to generate a first dark current;
- a first photodiode electrically connected to the first dark diode in series and configured to generate a photocurrent and a second dark current;
- a first operational amplifying unit connected to the first dark diode and the first photodiode;
- and
- an illumination calculator connected to an output terminal of the first operational amplifying unit;
- and
- a reference voltage setting unit configured to determine a reference voltage for the illumination sensing unit and to provide the reference voltage to a non-inverting input terminal of the first operational amplifying unit, the reference voltage setting unit comprising:
- a second dark diode configured to generate the first dark current;
- a second photodiode electrically connected to the second dark diode in series and comprising a light shielding film for generating the second dark current;
- a second operational amplifying unit connected to the second dark diode and the second photodiode;
- and
- a voltage setting unit connected to an output terminal of the second operational amplifying unit and configured to determine the reference voltage,
- wherein the reference voltage is determined to compensate for an offset voltage of the first operational amplifying unit and a difference between the first dark current and the second dark current.
17 more elements
Dependencies are inferred from the claim text.